Antimicrobial compositions include materials which have the ability to disinfect. It is generally recognised that a disinfecting material greatly reduces or even eliminates the microorganisms existing on a surface. Compositions based on halogen containing compounds like hypochlorite, or on quatemary compounds, have been extensively described in the art for disinfecting purpose. Compositions comprising peroxygen bleaches are also known as disinfecting compositions.
Representative of the prior art is, for example, WO88/00795 which discloses liquid disinfecting compositions comprising a compound selected from the group of organic acids, perborates. peracids and their salts, together with other antimicrobial compounds like a quaternary ammonium salt and an essential oil.
However, such disinfecting compositions are not fully satisfactory for the consumer who is looking for an effective disinfecting composition which can be easily used in various disinfecting applications, for example, in a spray form, while providing effective disinfecting performance even upon prolonged storage periods.
Indeed, a drawback associated with liquid compositions comprising a bleaching agent and an essential oil is that said liquid compositions tend to be chemically unstable upon prolonged storage periods. Indeed, traditional essential oils are usually made by a blend of components including terpenes, esters, aromatic components, chetones, aldehydes and the like. Said essential oils are sensitive to peroxygen bleaches. In other words, said essential oils show significant instability in presence of peroxygen bleaches and tend to decompose/oxidise said peroxygen bleaches, therefore leading to a lowering of the total level of available oxygen in a composition comprising a peroxygen bleach with consequent chemical stability issues and disinfecting performance issues upon long storage periods.
It is therefore an object of the present invention to provide a liquid disinfecting composition comprising a peroxygen bleach which is chemically stable for prolonged storage periods while delivering effective disinfecting performance on clean surfaces, even when used upon highly diluted conditions, and which is convenient and safe to use by the user.
It has now been found that this can be achieved by providing a sprayable stable liquid disinfecting composition comprising a peroxygen bleach, an antimicrobial active of essential oil, and a shear thinning polymeric thickener. More particularly, it has been found that the liquid peroxygen bleach-containing compositions of the present invention comprising said antimicrobial active of essential oil, and said shear thinning polymeric thickener, exhibit improved chemical stability upon prolonged storage periods, as compared to the same compositions comprising an antimicrobial essential oil instead of said antimicrobial active of essential oil, while providing effective disinfecting performance on clean surfaces, i.e., surfaces being free of any organic and/or inorganic soils, even at high dilution levels, i.e., up to dilution levels of from 1:100 (composition:water).
Furthermore, it has been found that the sprayable liquid peroxygen bleach-containing compositions of the present invention comprising said antimicrobial active of essential oil and said shear thinning polymeric thickener, exhibit improved safety upon usage, as compared to the same compositions without said shear thinning polymeric thickener, while providing effective disinfecting performance on clean surfaces and excellent chemical stability upon prolonged storage periods. Indeed, an advantage of the liquid compositions of the present invention is that the inhalation by the user of said compositions is prevented or diminished, when dispensing said compositions onto a surface to be disinfected via a spray-type dispenser. Thus, the compositions herein allow to avoid potential health issues like nose and/or throat irritation and/or coughing or even lung damage, that may otherwise occurs from inhalation of peroxygen bleach mist or fog that may have formed when spraying onto a surface a peroxygen bleach-containing composition being free of said shear thinning polymeric thickener. A further advantage of the present invention is that also eye irritation and/or damage is prevented when spraying a liquid composition according to the present invention.
Another advantage of the present invention is that the liquid compositions comprising a peroxygen bleach, an active of essential oil and a shear thinning polymeric thickener are easily dispensed onto the surface to be disinfected via a spray-type dispenser (e.g., a manually operated trigger-type dispenser). Indeed, said compositions result in a shear thinning behaviour for ease of dispensing, i.e. said compositions are thinner at higher shear rates. Thus, said compositions pass easily through the pumping mechanism of a spray-type dispenser where the shear rate is high and immediately after recover their thickened character when reaching the surface to be treated and adhere thereto. Also, the life time of a spray-type dispenser head is extended, i.e. the shear thinning behaviour of said compositions prevents clogging of said head.
Another advantage of the present invention is that sprayable liquid disinfecting compositions may be applied uniformly to a relatively large area of a surface to be disinfected via a spray-type dispenser, thereby ensuring effective disinfecting performance. Effective disinfection is provided on a broad range of pure bacterial strains including Gram positive and Gram negative bacterial strains and more resistant micro-organisms like fungi.
A further advantage of the compositions of the present invention is that besides the disinfecting properties delivered, good cleaning is also provided, especially in the embodiment of the present invention where the compositions herein further comprise a surfactant or a mixture thereof.
Also, the compositions according to the present invention are suitable to be used on all types of surfaces including animate surfaces like human skin, or mouth (e.g., as an oral preparation or toothpaste) as well as inanimate surfaces like hard-surfaces and in laundry applications, e.g., as a laundry detergent, laundry additive or even laundry pretreater. More particularly, an advantage of the compositions according to the present invention is that they are suitable to be used on delicate surfaces including those surfaces in contact with food and/or babies in a safe manner. Furthermore, when using the compositions according to the present invention in diluted conditions, the amount of chemical residues left onto the surfaces is reduced. Thus, it may not be necessary to rinse, for example, a hard-surface after said compositions have been applied thereto in diluted conditions.